Spiral broaching appliance.



R. R. LAPOINTE.

SPIRAL BROACHING APPLIANCE.

APPLICATION FILED' MAY 16, 1912 1 ,2]. 1 9 1 q Patented Mar. 6, 1917.

sachusetts,

- tion, like letters on operate with control the movement thereof in relation to I a work-piece its sides for OFFICE;

RALPH n. LAIPOINTE, or Henson,- massnenusn'r'rs, ASSIGNOB 'ro LAPOIN'IE MACHINE TOOL oomrm, or HUDSON, massacnusnrrs, A conromrron or mam.

' SPIRAL snoacnnve APPLIANCE.

Specification of Letters Patent.

To all whom it may concern:

Be it known that I, RALPH R. citizen of-the United States, and resident of Hudson, county of Middlesex, State of Mashave invented .an Improvement in Spiral the following descri tion; in connection with the accompanying rawings, is a specificathe drawings representing like parts.

The present invention relates to apparatus for producing spiral .broach cuts, and, more particularly, to an appliance adapted to coa spiral broach to guide and so that it is effective for producing the desired spiral path in the work.

More particularly the invention has to dov with improved means for causing the timed rotation of the broac'h relative to its reciprocation and by the same driving impulse as effects its reciprocation.

he invention will be better understood from. the following detailed description, taken in connection with the accompanying in the appended claims. I Referring "to the drawings,

Figure l is a side elevation of my improved appliance, fashioned in the manner adapting it to be applied to a standard form of broaching machine, the swivel connection of the. broach to its operating screw being shown in section;

Fig. 2 is a view in section on line 2-2 of Fig. 1, looking in the direction of the arrows; and 4 Fig. 3 is a view in section on 1ine-33 of Fig. 1.

l0 The broach indicated at 10 has a spiral rib 11 interrupted to form cutting teeth, ex-' tending through its operative portion. This broach is connected in a suitable manner,

shown as by a key 12 to a swivel head 13 -fitted to a bearing box 14 at the end of an operating screw 15, the engaging portions of the swivel head and its bearing box being shown as provided with an anti-friction ball bearing breaching machine is shown conventionally at 17, the broach passing centrally through this plate or head, as is usual. trative form of the invention shown a yoke member 18 is provided, having flanges 19 at securing the same to the head LA'POINTE, a

Broaching Appliances, of which work-piece a is dog 22, which set screw 25.

cut opening into rib 11 with the nut m 16. The face plate 01: head of a,

collar 20, this is merely illustrative, as In the illu s t e a d I he efore do not d sir to Patented Mar. 6,1917.

Application filed Iliay 16 1912. Serial No. 697,739.,

17. This yoke member has a nut portion 20 formed with a spiral channel or thread 21 of the spiral rib 11, which fits therein, the

in Fig. 3, to receive the highest or outer end portion of the spiral cutting rib. A hollow shown as fitted on the broach l0 and held from turning by the clamping has an arm 23 extending to engage the ,yoke 18, being shown at 24 as orked to, embrace and -fit aside of said yoke. This clamping dog is clamped to the workpiece in any suitable manner, shown as by a It may now be understood that. as the workpiece a is guided on thebroach and finds a backing against the machine head 17,

it will be acted 'n, by the spiral cutting rib' 11 of the broach, which will produce a spiral its central passage, corresponding 1n size and pitch to the rib 11. As

the broach is drawnon its cutting stroke through the work by the screw 15, or to the left in Fig. '1, it is given a definite and pre-- cise turning movement relative to its lengthwise movement by 11 in thespiral channel 21 of the nut portion 20 carried by the yoke 18, and the ex tent of turning movement relative to the longitudinal movement of the broach will correspond exactly to the spiral pitch of the rib 11, so that this rib will make a cut of its own spiral character through the workpiece, e., the cutting rib 11 will form a channel practically the same as that of the channel 21 in the controlling nut portion 20.

Theswivel connection afforded by the swivel head 13 and its box 14 with the anti-friction bearing between permits the broach to turn freely as required by which it fits," and thus the energy required for the cut is substantially only that involved in the engagement of the cutting rib with its land in the work-piece.

' I am' aware that my invention can be varied in numerous respects without departing from the spirit thereof; f r amp h l the nut portion 20 is shown as an inserted are also various of the other features of conbe limited in these or in other respects, except as setforth in the appended claims.-

the engagement of the rib suitably fashioned to conform .to the pitch a the engagement of the Having describedmy invention, what I claim as new and desire to secure by Letters Patent is:'

4 1. Apparatus of the kind described, comprising abroach provided with spiral cuttin means and anoperating mechanism for reciprocating the same, a swivel connection" from'the inner end of the broach to said operating mechanism, a machine frame work having a head equipped with means for holding a work iece against rotation, and means for efi'ectlng turning of as it moves longitudinally, said latter means being formed and mounted to engage said spiral cutting means at the outer end por' tion of the broach outside of and adjacent the work piece.

2., Apparatus of the kind described, comprising a broach having a spiral cutting rib and operating mechanism for reciprocating the same, a swivel connection from said broach to sa1d operating mechanism, means for mounting awork piece and holding it against rotation, and a fixed guide having a spiral channel adapted to engage and direct the broach said spiral rib to efi'ect a controlled rotar-y movement of the broach as it moves-lengthwise, said guide being mounted in position. I

to engage the tively close to the work piece.

3. Apparatusof the kind described, comprising a broaching machine head, a broach mounted for reciprocation through said head and having a spiral cutting rib, a yoke formed for removable attachment to said broach outside of and relamachine. head and having a guide passage 7 for 'the outer end of said broach provided with a channel for receiving and fitting said rib whereby said broach is caused to turn: as it moves endwise, ing a portion arranged to engage said yoke for holding a work piece against rotation on said broach as it is operated on thereby.

In testimony whereof, I have signed my and a clamping dog havname to this specification, in the presence of witnesses:

ALPH R. LAPOINTE. Witnesses:

C. L. Romans, R. G. Hunsnr.

two subscribin 

